Filterless Optical Discrimination for Multiplexed Fluorescence Detection
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Solution Overview
Problem
Current fluorescence-based optical discrimination systems for nucleic acid sequencing are complex and expensive due to the use of multiple filters and dichroic mirrors, and are not easily adaptable to new fluorescent dyes that may fluoresce at different wavelengths.
Innovation Solution
A filter-less optical discrimination apparatus using a multi-color light emitter, a sample holder, spectrally-dispersive element, and spectral detector to collect and disperse light orthogonally, allowing for the detection of multiple fluorophores without the need for filters or dichroic mirrors, and enabling the use of multiple excitation wavelengths without structural changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple filters and dichroic mirrors are used for each wavelength of excitation light, then fluorescence detection accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent removes filters and dichroic mirrors from the optical path, extracting the wavelength selection function to the detector side where a spectrograph disperses light and different wavelengths are detected at different positions on the CCD sensor. This eliminates the need for multiple optical filters while maintaining the ability to detect specific fluorescence wavelengths.
Solution Approach 2:
The patent transitions from temporal multiplexing (using filters/dichroic mirrors to sequentially select wavelengths) to spatial multiplexing (using a spectrograph to disperse wavelengths across different spatial positions on the detector). This dimensional change allows simultaneous detection of multiple wavelengths without requiring filter wheels or moving components.
2Adaptability or versatility
If separate filters and dichroic mirrors are used for each excitation wavelength, then adaptability to different fluorescent dyes is improved, but ease of operation deteriorates due to frequent component changes
Solution Approach 1:
The patent employs a universal spectrograph-based detection system that can detect any wavelength range without requiring physical component changes. The same optical path and detector can analyze fluorescence from any dye by simply changing the excitation wavelength, eliminating the need for filter wheel adjustments or component reconfiguration.
Solution Approach 2:
The system dynamically adapts to different fluorescent dyes by controlling the LED excitation wavelength rather than physically reconfiguring optical components. The spectrograph and CCD detector remain static while the excitation source is dynamically adjusted, simplifying operation while maintaining versatility.
3Measurement precision
If filters and dichroic mirrors are used to pass only specific wavelengths, then signal-to-noise ratio is improved, but loss of useful light increases
Solution Approach 1:
The patent removes filters from the optical path, extracting the wavelength discrimination function to the detection stage. Instead of blocking unwanted wavelengths with filters, the system allows all emitted light to reach the spectrograph, which then spatially separates wavelengths for detection. This eliminates the energy loss associated with filter absorption and reflection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system reduces complexity and cost, improves signal-to-noise ratio, and allows for adaptable use of various fluorescent dyes, achieving low detection limits and efficient multiplexed fluorescence detection.
Implementation Method 1
a multi-color light emitter configured to emit excitation light
Implementation Method 2
a spectrally-dispersive element configured to spectrally disperse the scattered light and the emission light into dispersed light spectra
Implementation Method 3
The fluorescent markers (fluorophores) are molecules that are capable of absorbing the filtered excitation light from the LED and emitting it at one or more well-defined wavelengths
Implementation Method 4
light emission collection optics configured to collect scattered light and emission light from the sample holder along a second direction that is approximately orthogonal to the first direction
Data Source
AI summary
An optical discrimination apparatus adapted for use in PCR testing and the like. The apparatus includes a multi-color light emitter to emit excitation light, a sample holder configured to hold dye-marked nucleic acid fragments in a PCR solution at a position configured to receive the excitation light along a first direction, light emission collection optics configured to collect scattered excitation light and light emission (fluorescent emission) from the sample holder along a second direction that is approximately orthogonal to the first direction, a spectrally-dispersive element configured to spectrally disperse scattered light and emission light, and a spectral detector configured to receive the separated emission light and excitation light on different photosites of the spectral detector. Systems and methods are provided, as are other aspects.